Comparison of pillar-array and hole-array patterned Si solar cells

Periodically patterned pillar-arrays and hole-arrays were applied to solar cells. A pillar has a width of 1.81 μm and a hole has a width of 2.28 μm in a similar periodic length of about 4 μm at a fixed depth of 2 μm. The three-dimensional patterns provide an optical benefit of reduction in reflection and thus, drive more photons into a Si absorber. From an electrical aspect, a patterned structure has a short carrier-collection length that results in an improved open-circuit voltage, yielding a value of 609 mV, which is better than the value of from 592 mV for a textured Si device.